Yeah... I'm going to go ahead and diagnose this as "Aliens".
It's probably Target Tracker creating print jobs in a weird way...
Have you contacted Target Tracker about this issue? maybe its a bug in their software that only happens under certain conditions.
In the mean time this may help...
Contact the people that coded the software it could be a bug. We had a good bug in our print management software a couple of years ago that .pub files over 2 pages took 40 pages of credit and it was fixed in the next release but was only one one printer and its driver so the solution before the new software was use the newer sibling printers drivers that worked on it as well and job done.
Could you print to PDF then print the PDFs? We had to do that to avoid an Excel 2010 issues with Toshiba drivers for our old copiers
Another option would be to
Prove the staf with the following items:
1x A4 pad of paper
1x Pencil Sharpener
Job Done :D
PS - replacements = 50p per replacement
What? That's what I had to make sure I had with me at school everyday - and they were checked at registration!
*hangs head in shame*
So that option was ticked on the other printers (working)? If not that may not be the cause but it may be a work around.
So its sorted?
If changing the "print background colours and images" tickbox makes a difference then it's likely that your target tracker is using encoding that quantifies the green colour as "Background" somehow.
I was going to say a common one for this sort of problem is when users tick the "monotone / monochrome" option in the print driver but I suspect you found the problem.
Target Tracker reports are all generated as HTML. As such, printing them is affected by IE's print settings. In Target Tracker, go to Print>>Print Preview. Click on "Page Setup" (It's a Cog icon). Put a tick in the box that states "Print background colors and images". Target Tracker's Helpline is open every weekday from 8 til 5 on 01245 213141.